I was just reading about a new yeast developed by Lallemand that produces lactic acid as a by product of fermentation. This allows brewers to create sour beers through the normal fermentation process. https://www.lallemandbrewing.com/en/united-states/product-details/sourvisiae/
Is it a "wild" yeast then? Eg is it just a lactobacillus saccharomyces blend, or does it do something to produce lactic flavours "through the normal fermentation process" (assuming they mean like "clean" fermentation brews?)
Here is the official blurb
QuoteSourvisiae® is a bioengineered ale yeast strain (Saccharomyces cerevisiae) capable of producing lactic acid during fermentation to provide brewers with an easy, reproducible, and mono-culture product for sour-style beer production.
Sourvisiae® contains a single genetic modification, a lactate dehydrogenase gene from a food microorganism, which enables the yeast to produce high levels of lactic acid, the main compound that gives sour beers their flavor. Sourvisiae® allows the brewer to ferment and sour the beer in one simple step, reducing cross-contamination risks, lowering costs, cutting total process time, and allowing brewers to obtain a consistent product. The brewing process is conducted without any modifications; Sourvisiae® is pitched just like conventional yeast and ferments in a normal fermentation time. Sourvisiae® does not produce other flavor compounds associated with Brettanomyces, Lachancea, or Lactic Acid Bacteria, providing a cleaner and more reproducible souring process, with much shorter fermentation times.
Sounds interesting, but i'm sceptical. Some one try it and report back, i don't want to be the first :D
I wonder if you can tweak the amount of sourness produced by ageing or temp, or is it stable in the level it produces...
Quote from: Jonnycheech on September 18, 2019, 05:46:51 AM
Sounds interesting, but i'm sceptical. Some one try it and report back, i don't want to be the first :D
I wonder if you can tweak the amount of sourness produced by ageing or temp, or is it stable in the level it produces...
From what I read it produces quite a lot of lactic and it's is extremely hard to control the amount of sourness that it produces.
QuoteSourvisiae® does not produce other flavor compounds associated with Brettanomyces, Lachancea, or Lactic Acid Bacteria
If that is the case, I don't see any advantage over just brewing with a normal yeast and adding in purified lactic acid. You'd have much more control over the amount of sourness that way.
Could be added at a point where the gravity has dropped say about half way. Limiting the remaining sugars would limit the available food for the lacto producing yeast.